C# in your browser
Real C# compiled by Roslyn, running on .NET WebAssembly — nothing leaves the page.
Runtime
The first Run downloads the C# compiler and the .NET runtime into a sandbox on a separate origin. Later visits load them from your browser's cache.
Not loaded yet — press Run to download the C# runtime.
- Downloaded
- —
- .NET version
- —
- Compiler
- Roslyn 5.0 on .NET 10, full library
C# scratchpad
Write top-level C# statements and run them. Stop ends a runaway program by shutting down its worker.
Output will appear here.
Experiments
Ready-made C# programs that show off the language. Each is compiled and run exactly like the scratchpad.
Pick an experiment.
Runtime probes
Ask .NET what it can see from inside the browser sandbox.
Probe results will appear here.